I share your concerns with chassis layout! Time and again I come up scrunching one thing to another. Space should not be a luxury. I use a 9" X 17" X 3" or something chassis and surprise myself more than once in a build. I remember once mounting a transformer sideways for the fit.
I'll share soon ( somewhere) pics of what I'm building now, for old ( not him old, but relation old) Customer - pair of unfortunate Aleph X monoblocks, where (except almost decent machining work) almost every detail is/was of subpar quality level ......... tossing that mess out and putting Singing Bush channels in
boy, dunno how many hours I already invested in reworking mechanic details ( planning, drilling, mounting etc.), and fact that I'm going to reuse dual-rail cap bank with 40Vdc screw-type caps, now connected in series, to get them adequate for 65Vdc one-rail arrangement, did enormous addition of time
space is so tight that every detail bloody counts ....... and it is going to be even funnier when I send proper length e-mail, explaining lengthy and exact! procedure how to mount glass front, which is left in Poland prior to shipping, to save it from damage
dunno, I think I'm already at 20+ hours invested in each monoblock, and just tomorrow starting to mount channel pcbs
aha, just remembered that I made few pics already
cap bank, just to illustrate up to what measure of compression/zipping I need to go ..........
that black thing underneath - that's top plate/cover
boy, dunno how many hours I already invested in reworking mechanic details ( planning, drilling, mounting etc.), and fact that I'm going to reuse dual-rail cap bank with 40Vdc screw-type caps, now connected in series, to get them adequate for 65Vdc one-rail arrangement, did enormous addition of time
space is so tight that every detail bloody counts ....... and it is going to be even funnier when I send proper length e-mail, explaining lengthy and exact! procedure how to mount glass front, which is left in Poland prior to shipping, to save it from damage
dunno, I think I'm already at 20+ hours invested in each monoblock, and just tomorrow starting to mount channel pcbs
aha, just remembered that I made few pics already
cap bank, just to illustrate up to what measure of compression/zipping I need to go ..........

that black thing underneath - that's top plate/cover
Attachments

Although, I do have a knack for making things at least 10 times harder than they need to be 😂
I got my baseplates last night. When running through my initial checks, I found that I had made two eesny-weensy ookups. I figured out what I had done, or not done in my specific case, and it is now finished. #protip - if you want the screen and remote / logic to work, it's best to provide power to it. 
First impressions are that it is absolutely incredible. It's currently running balanced in / SE out. When I get the other two channels of the ZD25 in a chassis and the balanced configuration set up, I'll give balanced in/out a try.




First impressions are that it is absolutely incredible. It's currently running balanced in / SE out. When I get the other two channels of the ZD25 in a chassis and the balanced configuration set up, I'll give balanced in/out a try.




forgot to order Kosher Dia & color button from Modu ........... even having proper recess for it
been there, done that

LOL! Next order.
forgot to order Kosher Dia & color button from Modu ........... even having proper recess for it
been there, done that
![]()

I do have proper color though. I like the silver on black. The button still works perfectly with the knob I used. Nice short press, and it does not touch the front panel. I like it... but I'll try the "correct" part.
that black thing underneath - that's top plate/cover
wasn't totally happy with shown arrangement, spent another chunk of time reworking, that cap bank is part of bottom plate
sorta overwater bungalow approach

With toroid, I can't leave it alone. I often put a rubbery pad on the bottom and then use the top rubber pad as expected.
Insert “Fugly!” here please.
Nice job IAIMH…didn’t realize you went for the balanced iteration.
Mine will be SE.
I did grab the Iron Pre in balanced and eventually hope to build that with a Muses logic control. Then I’ll finally have a reason to rewire my Babelfish J2 inputs and see if it appeals to me.
Nice job IAIMH…didn’t realize you went for the balanced iteration.
Mine will be SE.
I did grab the Iron Pre in balanced and eventually hope to build that with a Muses logic control. Then I’ll finally have a reason to rewire my Babelfish J2 inputs and see if it appeals to me.
Thank you.Insert “Fugly!” here please.
Nice job IAIMH…didn’t realize you went for the balanced iteration.
Most of the time, I run balanced from source through amp, but the amp I'm fiddling with now doesn't have a differential input stage. The Iron Pres / Pumpkins have the super-cool SE to 'true' differential / balanced trick, and to me that's one of the niftiest features, and why I used the IP balanced and now the balanced Pumpkin. Incredibly versatile (and quiet). I haven't done any measurements on the Pumpkin yet. Too busy listening. 🙂
Sweeeeeet!Mine will be SE.
I am pretty sure you'll love it. Someone else I know just finished building theirs. They're not typically easily impressed with anything, and they love it. They're also adding a Muses soon, I believe.I did grab the Iron Pre in balanced and eventually hope to build that with a Muses logic control.
It DEFINITELY will, IMO. Hmmmmmm.... I may have to pull mine out.Then I’ll finally have a reason to rewire my Babelfish J2 inputs and see if it appeals to me.

I have, but just for a super quick bench test verifying gain. I've only listened with unity (so far). When I switch to SE inputs, and/or try with another source with lower output, I'll likely bump it. Gut says that with these speakers and this amp... It will wind up at 6dB. My Iron Pre was at 6dB, and it was just about perfect.@ItsAllInMyHead
I see you're running unity gain...have you tried any of the other gain settings?
With other amps and speakers... I am not sure. I just love the versatility.
One of the reasons I really liked the idea of the Pumpkin / AVC is clarity at lower volumes / higher attenuation. I have speakers that run from 86dB @ 2V8 / 1m to 98dB @ 2V8 / 1m and amps that go from unity up to 20dB of gain (maybe more??) along with some flamethrower sources that I could easily run without a pre to some weeny sources that I still really like.
I listen at "don't wake up wifey" levels... all the way to "block party" levels.
I'm becoming more and more confident, that this pre will help cover all bases. It's particularly true when I've got a high gain amp, flamethrower source, and more efficient speakers, and I want to listen quietly in the morning and not lose all the detail. That's a nice thing to have.
Plus... so far... WOW! Just WOW!
Oh, there's a need. Definitely a need. Volume has already gone to 24.no reason, if there is no need

Last edited:
- Home
- Amplifiers
- Pass Labs
- Iron Pumpkin(s) and other smaller vegetable animals